1. Field of the Invention
This invention relates to a guide apparatus that may be use for installing generally cylindrical structures into a prepared hole in a substrate. More particularly, the invention guide is suitable for guiding a large pole, such as a utility pole, into a prepared hole in a ground surface.
2. Description of the Related Art
The efficient and safe installation or removal of large poles, such as utility poles, has long presented a challenge to those persons routinely engaged in this endeavor. For example, U.S. Pat. No. 608,193 which issued in 1898 disclosed a derrick for installing telegraph poles. The structure disclosed included a suitable mast adapted to be placed in the hole; an I-beam for guiding the lower end of the telegraph pole into the hole; and a derrick structure for raising or lowering the pole. The I-beam used to guide the lower or butt end of the pole into the receiving hole was equipped with a protruding V-shaped bar. Since telegraph poles were typically wooden, the butt end of the wooden pole would ride during installation against the V-shaped bar, causing a groove to form in the pole around the V-shaped bar. Thus, the V-shaped bar and cooperating groove in the pole would act to stabilize the telegraph pole while it was being inserted into the ground.
For elongate telegraph or utility poles, the possibility of swaying pole movement while suspended by a lifting mechanism during installation or removal was always present. There was, thus, a possible danger that sideways or swaying movement of the pole, while it was being lifted or failure of the wood surrounding the groove could dislodge the pole from the V-shaped bar. This would cause the pole to move away from the I-shaped guide beam. If the pole was partly in the hole, it would gouge into the side of the receiving hole. This would then necessitate the laborious process of removing the pole, emptying the hole of dislodged earth, repairing the hole, resetting the apparatus, and restarting the telegraph pole raising operation. Further, the use of the V-shaped groove forming bar as a guide for lowering telegraph poles would clearly not be suitable if the poles were fabricated from metal.
Subsequently, other approaches have typically used a flat board or plate as a guide for inserting poles into holes in the ground. For example, U.S. Pat. No. 2,138,842 discloses a pole-setting device which could be attached to the front end of a truck so that forward movement of the truck raised the pole. To guide the pole into the receiving hole, a flat board was placed in the hole so that the butt end of the pole slid against and down the length of the board when the pole was being inserted into the hole. A board used in a similar manner was shown in U.S. Pat. No. 2,725,991. However, in practice, when wooden boards were used with modern large utility poles, the boards would often fracture or the pole slide from the flat surface of the board and gouge or damage the sidewall of the hole. This required removal of the pole, frequently by manual operation, thereby increasing the risk of injury to workers and causing costly time delays in pole erection.
There is thus a need for a pole installation guide that reduces the risk that the butt end of a pole would move or sway and gouge the sidewall of the hole, that would not tend to break under the weight of a large utility pole, and yet that would be sufficiently light in weight and simple to use, and inexpensive to fabricate.